This invention relates to light converters and, in particular, to a circuit and method for providing a visible light energy response to an event in real time.
Devices which convert sound waves into light energy using an incandescent light source have been in use for some time. However, in such incandescent devices, there is a substantial inherent time delay between the occurrence of the sound stimulus and the appearance of a corresponding light response. This is due, in part, to the fact that incandescent filaments cannot respond quickly enough to the sudden changes in input voltage required to provide real time response to a rapidly changing sound input. A typical incandescent light filament has an inherent on-time delay, or "heat-up time", of about 200 milliseconds. Similarly, once the power to an incandescent light is turned off, another 200 milliseconds is required for the filament to cool down.
Use of other types of light sources with faster response times, such as neon tubes, has been inhibited by the large input voltage and 60 cycle frequency required to drive such sources sufficiently to achieve even ionization of the gas over the entire length of the tube. To generate the high voltage typically required to drive light sources of this type requires a large transformer. Because of the iron core and the large diameter of the transformer winding and hence, its mass, transformers of the size required to develop the high voltage necessary in these applications also have high inductance, intercapacitance and low coupling efficiency. Therefore, these transformers cannot generate the high frequency response required to provide real time sound-to-light conversion.
It has been found that when sound or music is accompanied by visible light in real time, the perception of the sound or music is greatly enhanced by the presence of a simultaneous corresponding light stimulation.
FIG. 1 shows a topological mapping of the human brain according to Broodmann (see Broodmann, 1852). The neural systems associated with sound-to-light stimuli are as follows: areas 17, 18 and 19 are the primary, secondary and tertiary systems of visual processing, respectively, and area 22 is the primary system of auditory processing. Broodmann, however, failed to detect functional capacity in the inferior-superior parietal lobe (ISPL). Therefore, the ISPL is not numerically differentiated in Broodmann's mapping.
Conventional wisdom holds that the ISPL is involved with abstract cross-modal interfacing of discrete sensory modalities. (See Pribram: Languaqe and the Brain; 1972). Stimulation of the ISPL generates an electrochemical response within the brain which spreads across the entire neocortical surface, thereby creating a meta-sensory state of consciousness. Due to the differences in the time element associated with various external sources of stimuli, e.g., the different speeds of sound and light, the ISPL is activated upon the receipt of messages generated by lower order collateral systems and redundant circuits which merely attempt to simulate simultaneity. However, the simultaneous firing of the neural systems for both auditory processing and visual processing is a necessary precondition for the ISPL system to fire cleanly, thus bypassing redundant and collateral systems. In other words, a more enriching experience is provided if a sound performance and an accompanying light display are perfectly synchronized.
However, a synchronized sound/light performance is not the only situation in which a real time light response to an event is desirable. For example, as stated above, an incandescent light bulb requires about 200 milliseconds to heat up to full brightness. For two cars travelling in the same direction at 60 miles per hour, this incandescent heat-up time correlates to about 17.6 feet that the second car will travel between the time that the driver of the first car applies the brake and the time that the driver of the second car sees the brake light of the first car. If the brake lights of the first car went on at the same time that its brake pedal was applied, the second car could begin braking 17.6 feet sooner.
Moreover, if the brake light were a tube of rare gas, such as neon, the light would be brighter, more efficient and more visible in bad weather. According to Samuel C. Miller, "Neon Techniques and Handling," 1977, incandescent light bulbs operate at about 8% efficiency, whereas neon is about 15% efficient in red. This means that a neon brake light would have almost 50% more light output than the conventional incandescent brake light for the same power applied. Miller also states, in the same source, that neon radiates light energy at 6000 Angstroms visible red wavelength. This means that it can be seen at greater distances through fog and bad weather by about 30%, or about 1.3 times further than an incandescent source which radiates in the 4500 Ansgstroms range.